Flash memory has gained widespread use in consumer devices and appliances where data secrecy and authenticity are substantial requirements. Several techniques are used to provide secrecy and authenticity for data on a flash memory device. The security mechanism may be implemented in the flash memory device driver and associated operating system implementation.
Encryption and decryption of data is common in computer data storage devices. Cryptographic techniques are often employed when storing data. While the employment of such techniques offer a level of security from unauthorized access, different computer platforms utilize the same cryptographic methods when storing and reading data from storage devices. These methods include, but are not limited to, Data Encryption Standard (DES), Advanced Encryption Standard (AES), and SHA (Secure Hash Algorithm) functions. Because different platforms employ common cryptographic methods, it is possible to remove a storage device from one computer and read the encrypted data on another computer which uses the same methods if one has access to the key. For adequate security, the key should not be a common key for every platform, or the security would rely on the secrecy of that single key only.
In some applications, message authentication codes (e.g., HMACs) are used to provide authentication verification data for message blocks. The storage of a MAC in the data block should give rise to acceptable data and read-write performance overhead. One desirable feature is to provide a method that is robust to bit errors in flash memory devices. Another desirable feature is that the data from multiple applications should be protected from each other in the operating system. That is, it should not be possible to use one application to gain access to control or modify another application or its data.
The USB flash drive is a common storage device using flash memory, for its relatively small size offers the end user ease of portability of computer information or data stored thereon. For instance, an end user can install the flash drive device on a USB port of one computer, store the information to the device, remove the device, install it on a USB port of another computer, and read the stored information. Even if the data may be encrypted by one platform, the data is not secure given the employment of common cryptographic techniques on other platforms unless the keys are protected by the platform. In addition, there are a variety of devices available to consumers which allow them to both read and write to the flash memory device. Thus, a further security mechanism is necessary to protect against security breaches of flash memory devices.
The foregoing examples of the related art and limitations related therewith are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the drawings.